1. Technical Field
The present invention relates to a technique for optically reading an object to be imaged.
2. Related Art
During scanning of an object to be imaged by an image forming device such as a color copier or the like having a scanner, reflection light from an original document is detected first within three wavelength ranges of red, green, and blue by a light receiving element such as a line sensor. Further, through predetermined image processing of obtaining a spectral reflectance for each wavelength range or so, multi-value image data consisting of four colors of yellow, magenta, cyan, and black is generated. As the number of wavelength ranges detectable by the light receiving element increases, the number of colors expressed by combinations of spectral reflectances for the respective wavelength ranges increases. Accordingly, images can be formed with colors reproduced with higher fidelity. In this respect, there has been a demand for a technique for reading an object to be imaged within as many wavelength ranges as possible, i.e., a technique for reading as many colors as possible from an object to be imaged.